Histiocytoid hemangioma with features of angiolymphoid hyperplasia and Kaposi's sarcoma. A study by light microscopy, electron microscopy, and immunologic techniques.

We examined by light and electron microscopy 99 vascular lesions removed on 17 occasions over a 2-year period from a 55-year-old black man. The lesions all showed histologic features of a vascular neoplasm composed of enlarged "histiocytoid" endothelial cells and overlapping features of angiolymphoid hyperplasia with eosinophilia and Kaposi's sarcoma. An apparently unique feature was early loss of melanin from the overlying epidermis and a mononuclear inflammatory-cell infiltrate. The patient also had an abnormal immunologic state very similar to that seen in homosexuals with Kaposi's sarcoma.